[114] Reid, Origin of the British Flora.
[115] Ludwig, Biologie d. Pflanzen.
[116] Ludwig, l.c., after Ihne, Frauenfeld, Shaw.
[117] Darbishire, Trans. and Proc. of Bot. Soc. Edin., vol. 23, part 1.
[118] Kerner, Natural History of Plants, vol. 2.
[119] Or whenever they could do so successfully. (Publisher's note.)
[120] Hackel, True Grasses.
[121] Hackel, True Grasses.
[122] De Candolle, Origin of Cultivated Plants.
[123] Drude, Handbuch Pflanzengeographie, p. 107.